I. Field of the Invention:
This invention relates in general to devices which will prevent the penetration of ultraviolet light and heat through vehicular windshields. More particularly, this invention relates to detachable devices which provide a removable reflective surface for the interior of vehicular windshields.
II. Description of the Relevant Art:
As is well known, heat build-up within a closed vehicle such as a boat, automobile, or airplane, can reach very high temperatures when that vehicle is parked for long periods in the sun. This is particularly problematic in warmer areas of the country which experience more intense and prolonged periods of sunshine. The interior vehicular heat build-up is uncomfortable for people who must enter such vehicles. This heat build-up places a heavy load on any air-conditioning equipment which may be present in the vehicle, shortens the life of the air-conditioning equipment, and increases operating costs. Even more damaging, are the effects of prolonged exposure to ultraviolet light which can damage and destroy the plastic, fabric and other materials within the automobiles. Additionally, and even more expensively, prolonged exposure to excessive heat can damage and destroy sensitive navigational and communications equipment such as the avionics present in aircraft.
Many windshield covers have been suggested and developed for attachment to the outer surface of windshields to inhibit ice formation thereon. These covers are often constructed of transparent sheets or plastic film. Such covers do not prevent heat build-up within the vehicle and are virtually useless in deflecting or preventing the penetration of ultraviolet rays.
A window cover system as disclosed in U.S. Pat. No. 4,209,197 is mounted on the exterior surface of all windows of an automotive vehicle. The covers are opaque and are intended for prevention of ice formation in the winter and heat build-up in the summer. As is the case with all exterior mounted covers, there can be problems with displacement due to wind, weight of snow, and the like. Additionally, these covers are prone to theft and can be easily lost.
The curtain structure of U.S. Pat. No. 4,109,957 is removably mounted on the interior surface of the vehicular windshield and the two adjacent side windows. The curtain is constructed of an opaque woven cloth material to provide privacy for the occupants of recreational vehicles, vans and the like. Because the privacy curtain disclosed in this patent is constructed of an opaque woven cloth, it will inherently reduce a certain amount of heat build-up if used for that purpose. However, since this cover was not intended for use in reducing heat build-up in vehicles, it is less than ideal for that purpose. Cloth materials while being effective for providing privacy, are not effective barriers to block solar radiation due to the porosity of the cloth.
U.S. Pat. No. 4,560,245 to Sarver discloses a vehicular screen which can be affixed to the windshield of an automobile. The curtain is formed of a flexible sheet of light-impervious material having a light colored outwardly facing surface and a dark inwardly facing surface which is light absorptive. The light colored outwardly facing surface of the windshield curtain reflects a large percentage of the sun's rays and the accompanying heat when fastened in place over the interior of a vehicle's windshield. The windshield curtain disclosed in Sarver is made of a heavy, thick laminated material which is difficult to fold and store. The material is generally rubber, silicone or the like, chosen for its flexibility and insulating characteristics. Such materials are susceptible to decomposition after prolonged exposure to ultraviolet radiation and can become brittle and crack.
The Sarver windshield curtain is adapted to be fastened to the windshield of the vehicle in a manner which permits a gap to exist between the inner surface of the windshield and the curtain. This configuration fails to enhance the limited capacity of the windshield to filter ultraviolet radiation.
Additionally, in the preferred embodiment, the Sarver device is designed to be maintained on the dashboard at all times. Thus, the curtain prevents the use of the dashboard for any dashboard-mounted devices such as compasses, citizen band radios or the like. Furthermore, the Sarver device is not readily adaptable for water vessels, aircraft, or automobiles which do not have the pronounced dashboards or complete dashboards. Additionally, the device must be lowered in a particular folded manner to ensure that the non-reflective surface is exposed when the curtain is at rest on the dashboard. This is necessary to prevent glare and the like from distracting the operator of the vehicle.
Therefore, it would be desirable to provide a removable windshield screen which could be employed successfully on a variety of different mobile vehicles such as automobiles, water craft, and aircraft. It is also desirable that the windshield screen provide a high degree of reflectivity and imperviousness to ultraviolet rays and be adapted to be positioned against the windshield in a manner which enhances any ultraviolet filtering characteristics which the windshield glass may already possess. It is also desirable that the screen be constructed of a material which will not decompose upon prolonged exposure to ultraviolet radiation and is capable of a high degree of insulation and can be stored in a compact manner.